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Editorial
Residual shunting after treatment of a persistent
arterial duct
Maarten Witsenburg1*, MD, PhD; Ad J.J.C. Bogers2, MD, PhD
1. Department of Cardiology and Paediatric Cardiology, Erasmus MC, Rotterdam, The Netherlands; 2. Department of Cardiothoracic
surgery, Erasmus MC, Rotterdam, The Netherlands
In this edition of the journal, Kusa et al report on their experience
with catheter closure of residual shunting after surgical treatment of
a patent arterial duct1. They collected their patients over a 15 year
period, illustrating that this is a rather uncommon problem.
Especially with present day surgery, it should be rare in experienced
hands. The question can be raised why a residual duct needs
closure anyway, especially when its haemodynamic significance
frequently will be small.
In foetal life the arterial duct is an important vessel. It connects the
main pulmonary artery to the descending aorta and has a diameter
comparable with that of the descending aorta. Due to the high
resistance in the foetal pulmonary vascular bed, the right ventricular
output mainly contributes to the systemic circulation via a “right-toleft” shunt through the duct. At birth, major changes occur. The
acute decrease in the pulmonary vascular resistance and increase
in systemic resistance result in a temporary “left-to-right shunt”.
Constriction of the duct after birth is induced by the rapidly
increased oxygen tension and decrease in circulating prostaglandin
and prostacyclin. Normally this results in functional ductal closure
within 48 hours2.
In prematurely born infants, ductal constriction is frequently
delayed. It may further compromise the ventilation of the premature
lungs in such tiny newborns, especially in those born before
30 weeks of gestation. Prostaglandin antagonists like indomethacin
and ibuprofen are used to facilitate ductal constriction. If this is not
successful, surgical closure via a small left lateral thoracotomy is the
ultimate solution. Catheter intervention in these babies weighing
much less then 1,000 grams is not an option.
Delayed ductal closure in term born infants is not uncommon. From
clinical experience it has become clear that when an arterial duct is
still open at three months after term birth, spontaneous closure will
not occur any more. The haemodynamic consequences of an
isolated persistent duct are a continuous left-to-right shunt from the
aorta to the pulmonary artery, resulting in a volume load of the left
heart. The shunt size will depend on flow restriction from the duct
(diameter and length) as well as the systemic and pulmonary
vascular resistance. A moderate or large duct may result in cardiac
failure due to the large volume load. Clinically, this becomes clear
three to six weeks after birth when the pulmonary vascular
resistance has reached its lowest value. A large non-restrictive duct
may ultimate lead to pulmonary vascular changes that increase the
pulmonary vascular resistance again and an Eisenmenger reaction
may occur after years.
A small duct will clinically be well tolerated during life, due to
absence of a significant volume overload. An arterial duct is called
“silent” when clinical signs like the typical continuous murmur are
absent and when it is found coincidently during routine
echocardiography.
Except for the “silent” ductus however, its common practice to close
all persistent arterial ducts, independent of shunt size because of
the significant risk of bacterial endarteritis. Historically the
incidence of endarteritis of the duct has been reported to be 1% per
year, and continuous to be a risk especially in less developed
countries3. It is likely that nowadays, the incidence of endarteritis is
much lower, with the present routine of surgical or catheter closure,
the use of antibiotics and a higher duct detection rate due to high
quality echo-Doppler equipment. The availability of safe and
effective catheter techniques has led to a practice of routine closure
of any persistent duct. Whether this should be advocated in a
coincidently found silent duct without a high velocity jet remains
* Corresponding author: Dept of Cardiology, Thoraxcenter, Erasmus MC, PO box 2040, 3000 CA Rotterdam, The Netherlands
E-mail: [email protected]
© Europa Edition 2008. All rights reserved.
EuroInterv.2008;3:539-540
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unclear4. In incomplete ductal closure, either after surgery or
catheter intervention, the endarteritis risk remains and forms the
major argument to try to close even a haemodynamically nonsignificant residual shunt.
Surgical closure of a persistent duct was first reported by Ross and
Hubbard in 19395. It is still used frequently in premature infants
and in young infants below the weight of four kilograms, who can
not be properly managed medically and in whom catheter
intervention is not yet feasible. Surgery is a quick and reliable
procedure where the arterial duct is clipped or doubly ligated and
divided. In infants over four kilograms, children and adults most
ducts can be closed with a catheter intervention.
The study of Kusa et al nicely illustrates the device development for
catheter closure of the ductus over the last two decades. Although
the first use of a transcatheter technique to close the duct with an
Ivalon plug was reported in 1967, the breakthrough came with the
report by Rashkind of the use of a “double umbrella” device in
19796,7. With this device, catheter closure became widely available.
However, for these devices, large introducer sheaths were needed,
which still prevented the use of this technique in young children
and infants. Residual shunting shortly after implantation was
frequently observed, but used to disappear in many patients within
months. In the 1990’s, the use of coils became popular for closure
of small to moderate ducts, also in smaller infants8. At first
Gianturco and other free release coils were used, but many
physicians nowadays will prefer coils with a controlled release
mechanism, like the Flipper (William Cook Europe ApS,
Bjaeverskov, Denmark) and the NitOcclud (PFM Medical, Cologne,
Germany). A more recent breakthrough is the development of a
specially designed Amplatzer duct occluder (AGA Medical
Corporation, Plymouth, MN, USA) which is now widely used for
ducts with a minimal diameter over 2-3 mm9-10. Full closure is
almost always obtained instantly.
Ductal morphology may vary from conical to tubular, so there is no
ideal device for every case. In addition to that, the use of large devices
in small babies may result in device protrusion in the aorta with
possible aortic obstruction. In those cases surgery is a well established
alternative, until improved catheter devices become available.
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The question whether all ducts need closure will continue to be
based on expert opinion, rather then on evidence. However, both
the surgeon and the cardiologist should aim for full closure, which
for the cardiologist means no residual shunt on the final aortogram
before the patient leaves the cardiac catheterisation laboratory.
Whenever a residual shunt remains, the indication for closure, and
the type of treatment have to be carefully discussed between the
cardiologist and the cardiac surgeon.
References
1. Kusa J, Szkutnik M, Czerpak B, Bialkowski J. Percutaneous closure of
previously surgical treated arterial duct. Eurointervention 2008;3:584-587.
2. Schneider DJ, Moore JW. Patent ductus arteriosus. Circulation.
2006;114:1873-1882.
3. Campbell M. Natural history of patent ductus arteriosus. Br Heart J
1986;30:4-13.
4. Thílen U, Astrom-Olsson K. Does the risk of infective endocarditis justify routine patent ductus arteriosus closure? Eur Heart J 1997;18:503-506.
5. Gross RE, Hubbard JP. Surgical ligation of a patent ductus arteriosus: a report of first successful case. JAMA. 1939;112:729-731.
6. Porstmann W, Wierny L, Warnke H. The closure of the patent ductus arteriosus without thoracotomy (preliminary report). Thoraxchir Vask
Chir. 1967;15:199-203.
7. Rashkind WJ, Cuaso CC. Transcatheter closure of patent ductus
arteriosus. Transcatheter closure of a patent ductus arteriosus: successful
use in a 3.5 kilogram infant. Pediatric Cardiol 1979;1:3-7.
8. Cambier PA, Kirby WC, Wortham DC, Moore JW. Percutaneous closure of the small (less than 2.5 mm) patent ductus arteriosus using coil
embolization. Am J Cardiol. 1992;69:815-1816.
9. Masura J, Walsh KP, Thanapoulos B, Chan C, Bass J, Goussos Y,
Gavora P. Catheter closure of moderate- to large-sized patent ductus arteriosus using the new Amplatzer duct occluder: immediate and short-term
results. J Am Coll Cardiol. 1998;31:878-882.
10. Wang JK, Hwang JJ, Chiang FT, Wu MH, Lin MT, Lee WL, Lue HC.
A strategic approach to transcatheter closure of patent ductus: Gianturco
coils for small-to-moderate ductus and Amplatzer duct occluder for large
ductus. Int J Cardiol 2006;106:10-15.